Flexible sheet material



FIG. 1 is a perspective view showing the ornamental design of a flexible sheet material according to the invention.

FIG. 2 is a further perspective view of the ornamental design of FIG. 1;

FIG. 3 shows an enlarged portion of the ornamental design of FIG. 1; and,

FIG. 4 shows another enlarged portion of the ornamental design of FIG. 1. 

The ornamental design for a flexible sheet material, as shown and described. 